Cup seals are known. There are, for example, the apparatus illustrated and described in U.S. Pat. Nos. 6,730,612; 6,706,641; 5,944,045; 5,787,928; 5,746,831; 5,704,977; 5,632,816. Gear pumps are known. There are, for example, the apparatus illustrated and described in U.S. Pat. Nos. 6,726,065; 6,183,231; 4,534,717; 4,400,147. The disclosures of these references are hereby incorporated herein by reference. This listing is not intended as a representation that a complete search of all relevant prior art has been conducted, or that no better references than those listed exist. Nor should any such representation be inferred.